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Updated: Jan 19, 2026

Determining the Optimal Inhibitory Frequency for Cancerous Cells Using Tumor Treating Fields TTFields
Published on: May 4, 2017
Optimization of Cancer Treatment in the Frequency Domain
Pascal Schulthess1,2, Vivi Rottschäfer3, James W T Yates4
1LYO-X GmbH, Basel, Switzerland.
Abstract:
Thorough exploration of alternative dosing frequencies is often not performed in conventional pharmacometrics approaches. Quantitative systems pharmacology (QSP) can provide novel insights into optimal dosing regimen and drug behaviors which could add a new dimension to the design of novel treatments. However, methods for such an approach are currently lacking. Recently, we illustrated the utility of frequency-domain response analysis (FdRA), an analytical method used in control engineering, using several generic pharmacokinetic-pharmacodynamic case studies. While FdRA is not applicable to models harboring ever increasing variables such as those describing tumor growth, studying such models in the frequency domain provides valuable insight into optimal dosing frequencies. Through the analysis of three distinct tumor growth models (cell cycle-specific, metronomic, and acquired resistance), we demonstrate the application of a simulation-based analysis in the frequency domain to optimize cancer treatments. We study the response of tumor growth to dosing frequencies while simultaneously examining treatment safety, and found for all three models that above a certain dosing frequency, tumor size is insensitive to an increase in dosing frequency, e.g., for the cell cycle-specific model, one dose per 3 days, and an hourly dose yield the same reduction of tumor size to 3% of the initial size after 1 year of treatment. Additionally, we explore the effect of drug elimination rate changes on the tumor growth response. In summary, we show that the frequency-domain view of three models of tumor growth dynamics can help in optimizing drug dosing regimen to improve treatment success.
Insights
Quantitative systems pharmacology (QSP) using frequency-domain response analysis (FdRA) optimizes cancer drug dosing. Analysis reveals tumor growth becomes insensitive to increased dosing frequency above a certain threshold, improving treatment strategies.
Area of Science:
- Pharmacometrics and Systems Pharmacology
- Control Engineering Applications in Biology
- Cancer Therapeutics Optimization
Background:
- Conventional pharmacometrics often overlooks detailed exploration of alternative dosing frequencies.
- Quantitative systems pharmacology (QSP) offers potential for novel insights into optimal dosing regimens and drug behaviors.
- Existing methods for QSP-based dosing optimization are limited, especially for complex models like tumor growth.
Purpose of the Study:
- To demonstrate the utility of frequency-domain response analysis (FdRA) for optimizing cancer treatment dosing regimens.
- To apply simulation-based frequency-domain analysis to distinct tumor growth models.
- To investigate the impact of dosing frequency and drug elimination rates on tumor growth and treatment safety.
Main Methods:
- Utilized frequency-domain response analysis (FdRA), a control engineering method, adapted for biological models.
- Analyzed three distinct tumor growth models: cell cycle-specific, metronomic, and acquired resistance.
- Performed simulation-based analyses to assess tumor size response and safety across various dosing frequencies and elimination rates.
Main Results:
- Identified a dosing frequency threshold beyond which tumor size is insensitive to further increases in frequency for all models.
- Demonstrated that certain dosing frequencies, like one dose per 3 days or hourly dosing, can yield similar tumor size reductions.
- Explored the influence of drug elimination rate variations on tumor growth response dynamics.
Conclusions:
- Frequency-domain analysis provides valuable insights for optimizing drug dosing regimens in cancer treatment.
- The findings suggest that excessive increases in dosing frequency may not improve efficacy and can be computationally inefficient.
- This approach can enhance treatment success by identifying optimal dosing strategies based on tumor dynamics.
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